7-7 Applying Percents

Warm UpWarm Up

Lesson PresentationLesson PresentationProblem of the DayProblem of the Day

Lesson QuizzesLesson Quizzes

7-7 Applying Percents

Warm UpFind the percent of each number.

1. 75% of 3002. 93% of 563. 32% of 1284. 9% of 60

22552.0840.965.4

7-7 Applying Percents

Problem of the DayA chessboard is 8 squares wide by 8 squares long. Each player has 8 pawns, 1 king, and 7 other pieces. At the start of a game, all the pieces are on the board, 1 piece per square. What percent of the total number of squares have a chess piece?50%

7-7 Applying Percents

MA.6.A.5.1 Use equivalent forms of fractions, decimals, and percents to solve problems.Also MA.6.A.5.3

Sunshine State Standards

7-7 Applying Percents

Vocabularydiscounttipsales tax

7-7 Applying Percents

Sales tax is an amount added to the price of an item.

sales tax = price • sales tax rate total cost = price + sales tax

Sales tax

A tip is an amount added to a bill for service. tip = bill • tip rate total cost = bill + tip

Tips

A discount is an amount that is subtracted from the regular price of an item. discount = price • discount rate total cost = price – discount

DiscountsCommon Uses of Percents

7-7 Applying Percents Additional Example 1: Finding Discounts A clothing store is having a 10% off sale. If Angela wants to buy a sweater whose regular price is $19.95, about how much will she pay for the sweater after the discount?Step 1: First round $19.95 to $20.Step 2: Find 10% of $20 by multiplying 0.10 • 20.

10% of 20 = 0.10 • $20 = $2.00The approximate discount is $2.00. Subtract this amount from $20.00 to estimate the cost of the sweater. $20.00 – $2.00 = $18.00Angela will pay about $18.00 for the sweater.

7-7 Applying Percents Check It Out: Example 1 A fishing store is having a 10% off sale. If Gerald wants to buy a fishing pole whose regular price is $39.95, about how much will he pay for the pole after the discount? $39.95 rounds to $40.10% of 40 = $440 - 4 = $36He will pay about $36.

7-7 Applying Percents

When estimating percents, use percents that you can calculate mentally.• You can find 10% of a number by moving the decimal point one place to the left.• You can find 1% of a number by moving the decimal point two places to the left.• You can find 5% of a number by finding one-half of 10% of the number.

7-7 Applying Percents Additional Example 2: Finding TipsBen’s dinner bill is $7.85. He wants to leave a tip that is 15% of the bill. About how much should his tip be?Step 1: First round $7.85 to $8.Step 2: Think: 15% = 10% + 5%

Step 3: 5% = 10% ÷ 2= $0.80 ÷ 2 = $0.40

Step 4: 15% = 10% + 5%.

Ben should leave about $1.20 as a tip.= $0.80 + $0.40 = $1.20

10% of $8 = 0.10 • $8 = $0.80

7-7 Applying PercentsCheck It Out: Example 2

Fran’s breakfast bill is $13.95. She wants to leave a tip that is 20% of the bill. About how much should her tip be?$13.95 rounds to $14.

2 1.40= $2.80

She should tip about $2.80.

10% of 14 = $1.40

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7-7 Applying Percents Additional Example 3: Finding Sales Tax Ann is buying a dog bed for $29.75. The sales tax rate is 7%. About how much will the total cost of the dog bed be?Step 1: First round $29.75 to $30.Step 2: Think: 7% = 7 • 1%

1% of $30 = 0.01 • $30 = $0.30Step 3: 7% = 7 • 1%.

= 7 • $0.30 = $2.10.The approximate sales tax is $2.10. Add this amount to $30 to estimate the total cost of the dog bed.

$30 + $2.10 = $32.10Ann will pay about $32.10 for the dog bed.

7-7 Applying Percents Check It Out: Example 3A

$19.83 rounds to $20.1% of 20 = $0.208 • 0.20 = $1.60.

20.00 + 1.60 = $21.60The total cost will be about $21.60.

Erik is buying a blanket for $19.83. The sales tax rate is 8%. About how much will the total cost of the blanket be?

7-7 Applying Percents Check It Out: Example 3B Diana is

$39.95 rounds to $40.1% of 40 = $0.408 • 0.40 = $3.20.

40.00 + 3.20 = $43.20The total cost will be about $43.20.

Diana is buying a rice cooker for $39.95. The sales tax rate is 8%. About how much will the total cost of the rice cooker be?